This invention relates generally to rolling element bearings and, more particularly, to a bearing shield suitable for extreme applications characterized by high rotational force on the bearing shield.
A bearing shield may be provided in a rolling element bearing assembly to close a side of the bearing so as to retain lubricant, to exclude foreign matter, to provide a more uniform outer bearing configuration, and to otherwise guard the rolling elements. The bearing shield is usually formed of metal and may incorporate provision for a resilient seal engaging the opposite bearing ring. Various bearing shield designs have been proposed, including some that have an interference or press fit of a lip of the bearing shield in a groove of a bearing ring to retain the bearing shield in the rolling element bearing.
Although such proposed bearing shields have achieved a simple axial installation with a degree of axial and radial retention, those designs have not always provided sufficient rotational retention. That is, the torque required to rotate the bearing shield with respect to the grooved outer bearing ring may be inadequate to prevent relative rotation. And, due to dimensional variations resulting from production tolerances, the torque required to rotate the bearing shield with respect to the grooved outer bearing ring is difficult to control with previous bearing shield designs.
Welding has not been used to attach a bearing shield to a rolling element bearing because of the detrimental effects of heat required to effect a weld between the bearing shield and a bearing ring. Typically the bearing rings are formed of heat-treated high carbon steel, and heat during welding could destroy the desired hardness and durability of the bearing ring, causing premature bearing failure. Also, rolling or sliding bearing surfaces may be damaged or welded together during the welding process, especially when electrical welding is used and arcing occurs between the rolling elements and the bearing rings.
The foregoing illustrates limitations known to exist in present rolling element bearings. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.